The common parasitic diseases of domestic animals are caused by the following groups of worms: Flukes or trematoides; tapeworms or Cestoides; thorn-headed worms or Acanthocephales; and round-worms or Nematoids. Flat worms, such as tapeworms and flukes, require secondary hosts. The immature and mature forms of tapeworms are parasites of vertebrate animals, but an invertebrate host is necessary for the completion of the life cycle of the fluke. The hog is the only specie of domestic animals that becomes a host for the thorn-headed worm. The round-worm is a very common parasite. There are many species belonging to this class.

[Illustration: FIG. 70.—Liver flukes.]

DISTOMA HEPATICUM (COMMON LIVER FLUKE).—Sheep are the most common hosts for this parasite. It is present in the gall ducts and livers, and causes a disease of the liver known as liver rot. The liver fluke is flat or leaf-like and from thirteen to fifteen mm. long (Fig. 70). The head portion is conical. It has an oval and ventral sucker, and the body is covered with scaly spines. The eggs are oval and brownish in color.

The life history, in brief, is as follows: Each adult is capable of producing an immense number of eggs which are carried down the bile ducts with the bile to the intestine, and are passed off with the faeces. Under favorable conditions for incubation, such as warm, moist surroundings, the ova or eggs hatch and the ciliated embryos become freed. The embryo next penetrates into the body of certain snails and encysts. The sporocyst, as it is now called, develops into a third generation known as redia which escape from the cyst. The daughter redia or cercaria, as they are now termed, leave the body of the snail and finally become encysted on the stems of grass, cresses and weeds. When taken into the digestive tract of the animal grazing over infested ground, the immature flukes are freed by the digestive juices. They then pass from the intestine into the bile ducts. The period of development varies from ten to twenty weeks; each sporocyst may give rise to from five to eight redia and each redia to from twelve to twenty cercaria.

Fluke diseases occur among animals pastured on low, wet, undrained land. Drying ponds and lakes are the homes of the fresh water snails, and in such places there are plenty of hosts for the immature flukes. Wet seasons favor the development of this parasite. Cattle and sheep that pasture on river bottom land in certain sections of the southern portion of the United States are frequently affected with fluke diseases.

The symptoms of liver rot of sheep may be divided into two stages. The first stage is marked by increase in weight and improved condition. In the second stage of the disease, the animal shows a pale skin and mucous membrane, dropsical swellings, loss of flesh and weakness. The character of the symptoms of the disease depends on the age of the animals and the care that they receive. Young, poorly cared for animals suffer severely from the disease, and the death rate is usually heavy. The finding of fluke ova in the faeces is conclusive evidence of the nature of the disease. It may be advisable to kill one of the sick animals, and determine the nature of the disease by a post-mortem examination.

[Illustration: FIG. 71.—Tapeworm larvae in liver (Echinococcus polymorphus).]

[Illustration: FIG. 72.—Tapeworms.]

The treatment is preventive. Drainage water from a pasture infested with snails harboring immature flukes is a source of infection, and should not be used as a water supply for cattle and sheep. In sections where the disease is prevalent, sheep should not be pastured on low, poorly-drained land. Such land should be used for pasturing horses and cattle, but if possible, it should be first drained and cultivated. Careful feeding and good care may help the affected animals to recover.

[Illustration: FIG. 73.—Tapeworm larvae in the peritoneum (Cysticercus cellulosa).]

TAPEWORMS OR CESTOIDES.—Tapeworms are formed by a chain of segments, joined together at their ends, and are flat or ribbon-shaped (Fig. 71). The head segment is small, and possesses either hooks or suckers. It is by these that the worm attaches itself to the lining membrane of the intestine. The anterior segments are smaller and less mature than the posterior segments. Each segment is sexually complete, possessing both the male and female organs, and when mature, one or more of them break off and are passed out with the faeces. The mature or ripe segments are filled with ova. On reaching the digestive tract of a proper host, usually with the drinking water or fodder, the embryo is freed from the egg. The armed embryo uses its hooklets in boring its way through the wall of the intestine. It then wanders through the tissues of its host until it finally reaches a suitable place for development (Figs. 71 and 73). On coming to rest, it develops into the larva or bladder-worm, which when eaten by a proper host gives rise to the mature tapeworm.

The following tables give the most important tapeworms:

ADULT FORMS

Name Host Organ

Taenia expansa Sheep and ox Intestine
Taenia fimbriata Sheep Liver
Taenia denticulata Cattle Intestine
Taenia alba Cattle Intestine
Taenia perfoliata Solipeds Intestine
Taenia mamillana Solipeds Intestine
Taenia echinococcus Dog Intestine

LARVAL FORMS

Name Host

Cysticercus bovis Cattle
Cysticercus cellulosa Swine and man
Cysticercus tennicollis Cattle, sheep and swine
Coenurus cerebralis Cattle and sheep
Echinococcus polymorphus Cattle, sheep, swine and man

The adult tapeworms Taeniae saginata and soleum, of which the Cysticerci bovis and cellulosa are the larvae forms, occur in man. The larvae are present in meat and pork, and this form of parasitism is termed beef measles in cattle and pork measles in hogs. Man becomes host for these two forms of tapeworms through eating measly pork or beef that is not properly cooked.

The dog is the host for Taeniae marginala, coenurus and echinococcus. The larvae forms of these taeniae are the Cysticercus tennicollis, Coenurus cerebralis and Echinococcus polymorphus. C. tennicollis is a parasite of the serous or lining membranes of the body cavities. It is not of great economic importance. C. cerebralis is a parasite of the brain of sheep, and may cause a heavy death rate in flocks that are infested with it. E. polymorphus is a parasite of the liver, but it may occur in other organs.

THE THORN-HEADED WORM OR ACANTHOCEPHALE.—This parasite requires a secondary host. In this case a particular species of the May-beetle larva or white grub that is commonly found about manure piles and in clover pastures is the host. The hog eats a white grub that is host for the larval form. The digestive juices free the larva, it then becomes attached to the intestinal mucous membrane and develops into the adult thorn-headed worm (Fig. 74). This parasite is characterized by a hooked proboscis or thorn at its anterior extremity, and the absence of a distinct digestive tract. The male is much smaller than the female. The eggs are passed out of the intestine with the faeces.

[Illustration: FIG. 74.—Thorn-headed worms.]

THE ROUND-WORMS OR NEMATOIDS.—Round-worms are very common parasites of domestic animals (Fig. 75). This group of worms is characterized by their cylindrical form, the presence of a true digestive canal and the separation into two sexes, male and female. The life history is more simple than in the flat worms. Intermediate hosts are not required for the development of the common forms. The eggs and embryos are deposited by the female in the intestinal tract, air passages, or excretory ducts of the kidneys of the host. Development may be completed here, or the eggs and embryos are passed off with the body excretions. They may live for a short time outside the animal body, or undergo certain development and again infest a host of the same species from which they came, through the water, grass and fodder that the animal may take into its digestive tract.

[Illustration: FIG. 75.—Large round-worm in intestine of hog.]

The following species of nematoids are common parasites of domestic animals:

SOLIPEDS

Species Organ
Ascaris megalocephala Intestines
Sclerostoma equinum Large intestine and blood-vessels
Sclerostoma tetracanthum Large intestine
Oxyrus curvula Large intestine
Oxyrus mastigodes Large intestine

CATTLE

Species Organ
Strongylus convolutus Abomasum
Ascaris vituli Small intestine (calves)
Strongylus ventricosus Small intestine
Oesophagostomum inflatum Large intestine
Trichocephalus affins Large intestine
Strongylus micrurus Bronchi
Strongylus pulmonaris Bronchi

SHEEP

Species Organ
Haemonchus contortus Abomasum
Ascaris ovis Small intestine
Strongylus filicollis Small intestine
Oesophagostomum columbianum Intestines
Uncinaria cernua Small intestine
Trichocephalus affins Large intestine
Strongylus filaria Bronchi
Strongylus rufescens Bronchi and air follicles

SWINE

Species Organ
Ascaris suis Intestines
Oesophagostomum dentatum Large intestine
Trichocephalus crenatus Large intestine
Trichina spiralis Muscles and intestines
Strongylus paradoxus Trachea and bronchi
Sclerostoma pingencola Renal fat and kidney

POULTRY

Species Organ
Ascaris inflexa Intestine
Spiroptera hamulosa Gizzard
Heterakis papillosa Caecum
Syngamus trachealis Trachea and bronchi

INTESTINAL WORMS OF SOLIPEDS.—The large round-worms or ascarides and the sclerostomes are the most injurious intestinal parasites of solipeds. The A. megalocephala or large round-worm is from 5 to 15 inches (12 to 35 cm.) long. It may be present in the double colon in such large numbers as to form an entangled mass that completely fills a portion of the loop in which it is lodged. It may interfere with digestion by obstructing the passage of alimentary matter, and irritating the intestine.

The S. equinum and S. tetracanthum are small worms. The former sclerostoma is from 0.6 to 1.5 inches (18 to 35 mm.) long, and the latter is from 0.5 to 0.6 inch (8 to 17 mm.) long. Both sclerostomes attach themselves to the lining membrane of the intestine by their mouth parts, and suck blood. The young S. equinum may live in tumor-like cysts that they cause to form in the lining membrane of the intestine. The young worm may penetrate the wall of a small blood-vessel as well, and drift into a large vessel, where it may become lodged and undergo partial development. The irritation to the blood-vessel results in an inflammation and dilation of the vessel wall. This is termed verminous aneurism. A portion of the fibrin-like lining of the aneurism may flake off and drift along in the blood stream, until finally a vessel that is too small for the floating particle or embolus to pass through is reached. The vessel is then plugged or a thrombus is formed. If the vessel involved by the thrombus happens to be a mesenteric vessel, then a loop of intestine has its blood supply cut off, and colicky pains result. Such colics are dangerous, and may terminate fatally. Intestinal obstruction, thrombo-embolic colics, unthriftiness and a weakened, anaemic condition may be caused by intestinal worms.

The treatment is both preventive and medicinal. The preventive treatment consists in giving young, growing animals the best care possible. Cleanliness about the stable, giving the colt plenty of range when running in a pasture, and feeding a ration that is sufficient to keep the colt in good physical condition are the important preventive measures. Tartar emetic in one-half to one dram doses may be given with the feed daily until five or six doses are given. Turpentine may be given in one to three ounce doses in a pint of linseed oil. This may be repeated daily for two or three days. Worms located in the posterior bowel may be removed by rectal injections of a weak water infusion of quassia chips. The rectum should be first emptied with the hand, and the nozzle of the syringe carried as far forward with the hand as possible. The injections should be repeated daily for several days.

INTESTINAL WORMS OF CATTLE.—Intestinal worms seldom cause serious losses from unthriftiness or death in cattle. It is in calves only that we are called on to treat this class of disease. The symptoms resulting from the invasion of the intestinal tract by the different worms vary in severity according to the number, habits of the parasite and care that the animal receives. The usual symptoms are unthriftiness, indigestion, diarrhoea and a stunted, anaemic condition. Stiles reported extreme anaemia, unthriftiness and many deaths among cattle in a certain section of Texas, due to extensive infection with the Uncinaria radialus.

The treatment is largely preventive. Calves and yearlings should be provided with plenty of feed at all seasons of the year. Good care and careful feeding will keep them in a thrifty, healthy condition and enable them to throw off invasions of intestinal worms. Turpentine is the vermifuge usually administered to calves. The dose is from two to four drams given in a milk or raw linseed oil emulsion.

STOMACH WORM OF SHEEP.—The twisted stomach worm, Haemonchus contortus, is the most injurious internal parasite of sheep. It is a very small, hair-like worm from 0.4 to 1 inch (9 to 25 mm.) in length. In the adult form it attaches itself to the mucous membrane of the fourth stomach or abomasum, and lives by sucking blood. The blood present in the digestive tract of the worm gives it a brown color, and the white oviducts which are wound around the digestive canal cause the body to appear twisted. When the twisted stomach worm is present in large numbers, the worms become mixed with the contents of the stomach and can be readily found on making a post-mortem examination.

Symptoms of stomach worms are first manifest in the lambs (Fig. 76). It is not until early summer that the disease appears in the flock. The symptoms are not characteristic unless we consider an unthrifty, anaemic, weak, emaciated condition accompanied by diarrhoea, during the summer months characteristic of stomach-worm disease. The sick animals are unable to keep up with the flock, and they like to stand about in the shade. They move slowly, the back is arched, the appetite poor, the mucous membranes and skin are pale and the hind parts soiled by the diarrhoeal discharge. More acute symptoms than the above sometimes occur. The disease may last from a few days to several weeks. A large percentage of the affected animals die.

[Illustration: FIG. 76.—Lamb affected with stomach worm disease.]

The treatment is largely preventive. Frequent changing of pastures and dry lot feeding are common preventive measures. Permanent sheep pastures lead to heavy losses from stomach worm disease. A very effective preventive measure, as we may term it, is the practice of administering a vermifuge to the ewes in the late summer and again in early winter. This may be given in a drench, or with the feed. This prevents the reinfection of the pastures every spring, and the young lambs are not exposed to this form of infection. The most effective treatment that the writer has ever used is the following formula recommended by Dr. Law: Arsenous acid one dram, sulfate of iron five drams, powdered areca nut two ounces, common salt four ounces. This is sufficient for one dose for thirty sheep. It may be given with the salt, or in ground feed. If the flock is apparently healthy, four doses given at intervals of three days is sufficient. If symptoms of stomach worms are manifested the animals should be dosed daily until they have received from five to ten doses, depending on the condition of the animal.

INTESTINAL WORMS OF SHEEP.—The most widely distributed and seemingly most injurious intestinal worm of sheep is the OEsopliagostomum columbianum. It is a small worm from 0.5 to 0.75 inch (12 to 18 mm.) long. It penetrates the lining membrane of the intestines and encysts in the intestinal wall. A tumor, varying in size from that of a millet seed to a hazelnut, then forms in the wall of the intestine. These tumors undergo a cheesy degeneration, and when mature, may appear as greenish, cheesy-like masses, covering a large portion of the lining membrane of the intestine. Diarrhoea and emaciation may result. These symptoms are most evident during the winter months.

The treatment recommended for ridding sheep of this intestinal worm is largely preventive. Very little can be done with the medicinal treatment of a sheep whose intestinal tract is badly infested with this parasite. Good care and the feeding of a proper ration are the only curative measures that are effective in such cases. The occasional administration of a vermifuge for the purpose of ridding the digestive tract of worms, together with the frequent changing of pastures during the spring and summer, are the most effective preventive lines of treatment. The same treatment recommended for stomach worms may be used for this disease.

INTESTINAL PARASITES OF HOGS.—The Ascaris suis or common round worm is very commonly found in the small intestine. It is quite frequently found in large numbers, almost filling the lumen of the intestine of an unthrifty pig (Fig. 75). It may also work its way into the bile duct. Sometimes, after a hog has died, this parasite migrates forward into the stomach and gullet. The A. suis is from 4 to 10 inches (10 to 26 cm.) long.

The Echinorhynchus gigas or thorn-headed worm is the most dangerous of all intestinal worms (Fig. 74). It is usually found with its proboscis or thorn imbedded in the wall of the small intestine. The Echinorhynchus is not as common a parasite as the Ascaride, and it is not usually present in large numbers. Usually, not more than a half-dozen of these worms are found in the intestine of a hog, but in some localities and in hogs that are allowed to root around manure piles and in clover pastures the herd may become badly infected with them and serious losses occur. The average length of the male is about 3 inches (8 cm.) and the female 10 inches (26 cm.).

[Illustration: FIG. 77.—Whip-worms attached to wall of intestine.]

[Illustration: FIG. 78.—Pin-worms in intestine.]

The Trichocephalus crenatus or whip worm (Fig. 77) is slender or hair-like in its anterior two-thirds and thick posteriorly. It is from 1.5 to 2 inches (40 to 45 mm.) long. It is found in the caecum attached to the wall by the hair-like portion.

The OEsophagostomum dentatum or pin worm is from 0.3 to 0.6 inch (8 to 15 mm.) long. It is found in the large intestine (Fig. 78).

The symptoms of intestinal worms are not very evident in the average drove of hogs. None of the other farm animals are such common hosts for intestinal worms as hogs. But it is only in extreme cases of infection by intestinal worms, and in stunted and poorly-cared-for hogs, that very noticeable symptoms of disease are manifested. We must not take from the above statement that it is unnecessary to resort to treatment unless in exceptional cases. Intestinal worms interfere with the growth of young hogs, and may irritate and inflame the intestine, causing chronic indigestion, nervous symptoms, and in some cases death. This irritated and inflamed condition of the intestine is best noted in the abattoir by the ease with which the wall of the intestine that contains large numbers of worms tears when handling it.

The treatment of intestinal worms in hogs is both preventive and medicinal. If the conditions in the pens and houses are such as to enable the eggs and embryos to live for a long time, or the surroundings are favorable for infection of the animals through their feed and water supply, the herd may become badly infested with intestinal parasites. The preventive treatment consists in keeping hogs in clean, well-drained yards or pastures, and feeding them from clean troughs and concrete feeding floors that can be washed, when necessary, in order to keep them clean. Turpentine, given in a milk emulsion, is a common remedy for intestinal worms in hogs. The dose is one teaspoonful for every eighty pounds weight. This dose should be repeated daily for three days. The following vermifuge can be recommended: Santonin three to five grains, calomel five to eight grains. This is sufficient for one hundred pounds weight. If the pigs are small and it requires two or three to weigh one hundred pounds, the large dose should be given. If the hogs weigh one hundred pounds or more, they should receive the small dose. The drove should be divided into lots of ten or fifteen hogs each. The drugs should be mixed and divided into the same number of powders as there are lots of hogs. Ground feed is placed in the trough, dampened with milk, or water and the powder sprinkled evenly over it. The hogs are then allowed to eat the feed. It is best to dose them in the morning after they have been off feed for ten or twelve hours.

VERMINOUS BRONCHITIS IN CALVES.—The lung worms of cattle, Strongylus micrurus and Strongylus pulmonaris, may cause heavy losses in calves and yearlings. Older cattle may harbor these parasites, but they do not seem to be inconvenienced by them. The S. micrurus is from 1 to 3 inches (25 to 75 mm.) long. The S. pulmonaris is smaller. It is from 0.4 to 1.3 inches (10 to 35 mm.) long. They are found in the trachea and small bronchial tubes, where they are mixed with mucous secretions from the inflamed lining membrane of the bronchial tubes.

Wet seasons and low, wet pastures are said to favor the development of lung worms. Their life history is not fully understood. They do not persist generation after generation in the air passages of an animal, but the eggs and embryos are expelled and live for a time outside of the animal, when they may again become parasites of another or the same host.

The symptoms are the same as occur in bronchitis and pneumonia. Calves and yearlings are the only animals in the herd that may show symptoms of the disease. The air passages become irritated and inflamed, and the calf shows a slight cough. As the inflammation increases and the worms and mucous secretions plug up the small bronchial tubes, the coughing spells become more severe and rattling, wheezing sounds may be heard on auscultating the lungs. The calf finally loses its appetite, becomes emaciated and weak, and wanders off alone. It is usually found lying down and shows labored breathing that is occasionally interrupted by paroxysmal coughing. The death rate in poorly-cared-for herds is heavy.

VERMINOUS BRONCHITIS AND PNEUMONIA OF SHEEP.—The two lung worms of sheep are the Strongylus filaria and Strongylus_ rufescens_. The former is from 1.3 to 3 inches (33 to 80 mm.) long, and the latter from 0.6 to 1 inch (16 to 25 mm.) long. The S. filaria is thread-like and the S. refuscens hair-like in appearance. For this reason they are termed thread and hair lung-worms. The thread-worm is found in the trachea and the larger bronchial tubes, and the hair-worm in the most minute as well as the larger bronchioli.

This disease is most common in wet seasons. Undrained pastures and ponds are said to favor the spread of the disease. Permanent pastures favor the reinfection of the flock from year to year. The eggs and embryos are expelled in coughing, and live for a time in the pastures, pens and houses. The sheep become infected through the dust, drinking water or feed.

The symptoms of verminous bronchitis and pneumonia are quite characteristic. Lambs suffer most from these diseases. A number of animals in the flock are affected. Coughing, rapid and labored breathing, loss of appetite, emaciation and weakness are the usual symptoms noticed. When a paroxysm of coughing occurs, considerable mucus is expelled. An examination of the expectorations may result in finding a few lung worms. In poorly-cared-for flocks, and when complicated by stomach and intestinal worms, the death rate is usually heavy.

The treatment of lung-worm diseases in lambs and calves is largely preventive. We should use every possible precaution against introducing the infection into the herd or flock. It is not advisable to bring animals from an infected herd onto the premises, without subjecting them to a careful examination and a long quarantine before allowing them to stable or pasture with the other animals. Calves or lambs that show marked symptoms of disease should be given comfortable quarters, and special care and feeding. The entire herd or flock must be given the best care and ration possible. This is the only satisfactory method of treatment. Changing the pasture or lot frequently may help in ridding the premises of the infection.

VERMINOUS BRONCHITIS IN HOGS.—The lung worm, Strongylus paradoxus, is a common parasite of young hogs. It is from 0.6 to 1.6 inches (16 to 40 mm.) long. When the infection is light, the worms are found mostly in the bronchial tubes of the margin and apex of the lung.

Infection with this parasite does not depend on the humidity of the soil, or low, wet pastures containing ponds. Probably dusty quarters are responsible in large degree for this disease.

The symptoms are most evident in pigs weighing from forty to eighty pounds. The first symptom is a cough, occurring on leaving the bed, after exercise and after eating. In badly infected cases the paroxysm of coughing is quite severe. The appetite usually remains good and the thriftiness of the pig is not seriously interfered with. The feeding of a suitable ration, and the good care that is usually given young hogs, are responsible for the mildness of the disease.

The treatment that is of most importance is clean quarters, and the feeding of a ration that will keep the pig growing and healthy. The sleeping quarters should be kept free from dust. Disinfectants should be used freely about the quarters.

THE KIDNEY WORM OF HOGS.—Sclerostoma pinguicola is the kidney worm of hogs. It is from 1 to 1.5 inches (25 to 27 mm.) long, and when seen against the kidney fat it appears dark or mottled. It is usually found in the fat in the region of the pelvis of the kidney. Although the kidney worm is capable of causing inflammatory changes in the tissues surrounding the kidney and the pelvis of this organ, the disease cannot be determined by any noticeable symptom. Paralysis of the posterior portion of the body is attributed to the presence of kidney worms by stockmen. There are no data by which we may prove that the kidney worm is responsible for this disorder.

The treatment is preventive. Clean feed, pens, watering troughs and feeding floors are the preventive measures indicated here. It is useless to attempt treatment with drugs, as the worms are out of reach of any drug that may be administered.

WORMS OF THE DIGESTIVE TRACT OF POULTRY.—Poultry are often seriously infested with worms. A small number of the less injurious worms may not cause any appreciable symptoms of disease; but the fowl that harbors them is a source of infection to the other fowls. The infectious nature of parasitic disease caused by worms should be recognized more fully than at present by poultrymen.

The different species of poultry are hosts for many different species of round-worms, thorn-headed worms and tapeworms. Dr. Kaupp states that Acaris inflexa or large round-worm, Heterakis pipilosa or small round-worm, and the Spiroptera hamulosa or gizzard-worm are frequently found in fowls. The common round-worm may be found in the first portion of the intestine, and the small round-worm in the caecum. Neither of the species are dangerous unless present in large numbers. They may then obstruct the intestine, and irritate the intestinal mucous membrane. This may cause constipation, catarrhal inflammation of the intestine and diarrhoea. The gizzard-worm is the most dangerous of the parasites mentioned. The gizzard has an important digestive function, and any condition that may weaken its muscular walls may cause serious digestive disorders. This parasite may encyst in the wall of the gizzard.

The treatment of intestinal worms in poultry is both preventive and curative. The preventive measures consist in keeping the houses and runs clean. Air-slaked lime should be scattered over the runs every few weeks. The drinking places should be cleaned and disinfected daily. All possible precautions should be taken in order to prevent filth from getting into the drinking water. Epsom salts, powdered areca nut and santonin are the remedies commonly recommended for the treatment of intestinal worms. From twenty to forty grains of Epsom salts may be given. Powdered areca nut is recommended in from three to ten grain doses. Santonin may be given in from one to two grain doses. Both the areca nut and santonin may be given with the feed.

THE GAPES IN BIRDS.—The gape-worm, Syngamus trachealis, is from 0.2 to 0.8 inch (5 to 20 mm.) long. The male and female are permanently united. The male is about one-third as long as the female, and when attached to the anterior third of the female, gives the pair a forked appearance.

Fowls become infested with the gape-worm by eating the adult parasite that has been expectorated, or an earth worm that is host for the immature parasite. The embryo gape-worm is freed in the intestine, and from here they are supposed to migrate into the abdominal air sacs and to the trachea and bronchi.

The symptom are most severe in very young fowls. The affected bird opens its mouth and appears to gasp for breath, sneeze and attempt to swallow. In the severe cases the appetite is interfered with, mucus accumulates in the mouth and the bird is dull and listless. The death rate is quite high in young-chickens and turkeys.

The treatment is both preventive and curative. If the gape-worm is known to be present in the runs, the ground should be covered with lime, and the fowls moved to fresh runs if possible. The young birds should not be exposed to the infection until they are well feathered out. Antiseptics may be given with the drinking water. Disinfectants should be used freely about the poultry houses, and the quarters kept clean. The worms may be snared by inserting a stiff horse hair that has been twisted and forms a loop into the trachea. This may be dipped into camphorated oil or turpentine. This treatment should be repeated until the bird has been relieved.

QUESTIONS

1. Name the different groups of internal parasites; give examples of each.

2. What conditions favor liver rot? Give the life history of the liver
fluke.

3. Name three common tapeworms; give the life history of the beef and pork
tapeworms.

4. Name the common intestinal worms of horses and give the treatment.

5. Give the symptoms and treatment of stomach-worm disease of sheep.

6. Name the common intestinal worms of hogs and give treatment.

7. What species of domestic animals suffer most of verminous bronchitis? Give the treatment.

8. Name the common internal parasites of poultry and give treatment.